The Black Mountains (Welsh: Y Mynyddoedd Duon) are a group of hills spread across parts of Powys and Monmouthshire in southeast Wales, and extending across the national border into Herefordshire, England. They are the easternmost of the four ranges of hills that comprise the Brecon Beacons National Park, and are frequently confused with the westernmost, which is known as the Black Mountain. To confuse matters further, there is a peak in the Black Mountains called Black Mountain.